DC and Warners have a lot of ground to cover in order to catch to Marvel's world-building, but their next expansion on this front will take place on the small screen. The next episode of Arrow, called "The Scientist," will introduce Barry Allen, a.k.a. The Flash, played by Glee's Grant Gustin.

Watch the clip of his introduction above.

We also have a full synopsis of this pivotal episode from The CW (via ComingSoon):

"A seemingly impossible robbery at Queen Consolidated’s Applied Sciences Division brings Central City police scientist Barry Allen (guest star Grant Gustin) to town. Citing a similar case back home, Barry offers to help Oliver and team with the investigation. Oliver senses there is more to Barry than meets the eye, but he’s distracted by the similarities between this current case and something that happened on the island. Meanwhile, Felicity takes a liking to Barry, which doesn’t go unnoticed by Oliver. Sin (guest star Bex Taylor-Klaus) asks Roy for help when a friend of hers goes missing. Roy is surprised when Thea not only encourages him to help, but joins the search. Unfortunately, Sin’s friend is connected to Brother Blood (guest star Kevin Alejandro), and their search ultimately gets one of them seriously injured."

Arrow executive producer Andrew Kreisberg also talked about this introduction of a major DC Comics character, who in this incarnation is a rather quirky police scientist from Central City. Kreisberg's commentary about this event includes footage from the Barry Allen introduction, and here it is:

The button at the end of the scene between Barry and Felicity (Emily Bett Rickards) is a clear reference to the superspeed powers which Barry will eventually have as The Flash, and while the showrunners consider this a big step forward for DC's shared multimedia universe, we also know that Gustin's Flash won't be super-powered during his run on Arrow. Instead, the mooted Flashseries will have a standalone pilot, but before that, Barry Allen will appear on at least one more episode.

In the previous DC continuity, Barry Allen was actually the second person to take up the mantle of the Crimson Comet, but DC's re-vamped New 52universe features a version of Allen in line with what we might be seeing on Arrow. DC Comics' official character breakdown features the following description:

CSI scientist Barry Allen was involved in a lab accident when a lightning bolt strike caused him to be doused in a strange mixture of chemicals. He emerged from the accident with powers that enabled him to run and move at incredible speeds. Barry learned that these powers come from his connection to an extradimensional energy known as the Speed Force, and seeing an opportunity to use his speed for good, began his adventures as the Flash.

Given the introduction of Gustin's character as a "police scientist," it sounds like we could actually expect this providential bolt of lightening in the Flash pilot to introduce our first legitimately extra-normal super-hero into the ever-expanding roster of characters. Since Arrow tends to be more grounded and "gritty," a random blast of electricity from the heavens will more likely be swapped out for something more motivated.

The synopsis notes that "Oliver senses there is more to Barry than meets the eye," which could mean almost anything - but it hints toward Barry Allen's future superpowers... or maybe his potential as a hero. This new link to Central City - The Flash's base of operations and now an established locale within the DC small-screen universe - clears the way for even more DC faces. We've already seen Amanda Waller (Cynthia Addai-Robinson), Sebastian Blood (Kevin Alejandro), Black Canary (Caity Lotz) and Isabel Rochev (Summer Glau), with Ra’s al Ghul’s daughter Nyssa (Katrina Law), Cyrus ‘Solomon Grundy’ Gold (Graham Shiels) and possibly Nightwing on their way.